Satoru Komatsu

Distance characteristics of electric field pattern for an antenna mounted on a car in UHF band

It is important to know distance characteristics of electric field pattern to measure radiation patterns for car mounted antennas. In this paper, distance characteristics of electric field pattern for an antenna mounted on a car in the UHF band are investigated by the electromagnetic simulation for the first time. As a result, it is shown that distance characteristics of electric field pattern are affected by polarization, frequency, antenna positions, and origin positions to define the distance.

Evaluating method of the on-board FM receiver characteristics using MUSIC method and the Two-Stage method

Although we have evaluated the characteristics of the FM receiver by repeated running tests. Thus, there have been issues in its reproducibility and objectivity. To solve this problem, we developed a Two-Stage method reproducing a virtual radio environment on a PC [1]. However the Two-Stage method also had problems in estimating the actual radio wave environment and the arrival of FM broadcast wave. Thus, estimation of incoming waves by experiment is necessary by using the likes of MUSIC (Multiple Signal Classification) method [2]. However, application of MUSIC method to FM reception has an issue in the separation performance for multipath waves in urban area due to constraints such as the number of array antenna elements. Consequently, MUSIC method with the use of virtual array antennas was developed [3]. In this study, the accuracy of MUSIC method-based estimation in actual environment was verified by modeling actual reception environment in urban area, and calculating values regarding radio wave environment characteristics with the use of a 3D map and ray tracing method.